<HTML>
<BODY BGCOLOR="white">
<PRE>
<FONT color="green">001</FONT>    /*<a name="line.1"></a>
<FONT color="green">002</FONT>     * Zmanim Java API<a name="line.2"></a>
<FONT color="green">003</FONT>     * Copyright (C) 2004-2008 Eliyahu Hershfeld<a name="line.3"></a>
<FONT color="green">004</FONT>     *<a name="line.4"></a>
<FONT color="green">005</FONT>     * This program is free software; you can redistribute it and/or modify it under the terms of the<a
        name="line.5"></a>
<FONT color="green">006</FONT>     * GNU General Public License as published by the Free Software Foundation; either version 2 of the<a
        name="line.6"></a>
<FONT color="green">007</FONT>     * License, or (at your option) any later version.<a name="line.7"></a>
<FONT color="green">008</FONT>     *<a name="line.8"></a>
<FONT color="green">009</FONT>     * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without<a
        name="line.9"></a>
<FONT color="green">010</FONT>     * even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU<a
        name="line.10"></a>
<FONT color="green">011</FONT>     * General Public License for more details.<a name="line.11"></a>
<FONT color="green">012</FONT>     *<a name="line.12"></a>
<FONT color="green">013</FONT>     * You should have received a copy of the GNU General Public License along with this program; if<a
        name="line.13"></a>
<FONT color="green">014</FONT>     * not, write to the Free Software Foundation, Inc. 59 Temple Place - Suite 330, Boston, MA<a
        name="line.14"></a>
<FONT color="green">015</FONT>     * 02111-1307, USA or connect to: http://www.fsf.org/copyleft/gpl.html<a
        name="line.15"></a>
<FONT color="green">016</FONT>     */<a name="line.16"></a>
<FONT color="green">017</FONT>    package net.sourceforge.zmanim.util;<a name="line.17"></a>
<FONT color="green">018</FONT>    <a name="line.18"></a>
<FONT color="green">019</FONT>    import java.util.Calendar;<a name="line.19"></a>
<FONT color="green">020</FONT>    import net.sourceforge.zmanim.AstronomicalCalendar;<a name="line.20"></a>
<FONT color="green">021</FONT>    <a name="line.21"></a>
<FONT color="green">022</FONT>    /**<a name="line.22"></a>
<FONT color="green">023</FONT>     * Implementation of sunrise and sunset methods to calculate astronomical times.<a
        name="line.23"></a>
<FONT color="green">024</FONT>     * This calculator uses the Java algorithm written by &lt;a<a name="line.24"></a>
<FONT color="green">025</FONT>     * href="http://www.kevinboone.com/suntimes.html"&gt;Kevin Boone&lt;/a&gt; that is based<a
        name="line.25"></a>
<FONT color="green">026</FONT>     * on the &lt;a href = "http://aa.usno.navy.mil/"&gt;US Naval Observatory's&lt;/a&gt;&lt;a<a
        name="line.26"></a>
<FONT color="green">027</FONT>     * href="http://aa.usno.navy.mil/publications/docs/asa.php"&gt;Almanac&lt;/a&gt; for<a
        name="line.27"></a>
<FONT color="green">028</FONT>     * Computer algorithm ( &lt;a<a name="line.28"></a>
<FONT color="green">029</FONT>     * href="http://www.amazon.com/exec/obidos/tg/detail/-/0160515106/"&gt;Amazon&lt;/a&gt;,<a
        name="line.29"></a>
<FONT color="green">030</FONT>     * &lt;a<a name="line.30"></a>
<FONT color="green">031</FONT>     * href="http://search.barnesandnoble.com/booksearch/isbnInquiry.asp?isbn=0160515106"&gt;Barnes<a
        name="line.31"></a>
<FONT color="green">032</FONT>     * &amp;amp; Noble&lt;/a&gt;) and is used with his permission. Added to Kevin's code is<a
        name="line.32"></a>
<FONT color="green">033</FONT>     * adjustment of the zenith to account for elevation.<a name="line.33"></a>
<FONT color="green">034</FONT>     *<a name="line.34"></a>
<FONT color="green">035</FONT>     * @author &amp;copy; Eliyahu Hershfeld 2004 - 2008<a name="line.35"></a>
<FONT color="green">036</FONT>     * @author &amp;copy; Kevin Boone 2000<a name="line.36"></a>
<FONT color="green">037</FONT>     * @version 1.1<a name="line.37"></a>
<FONT color="green">038</FONT>     */<a name="line.38"></a>
<FONT color="green">039</FONT>    <a name="line.39"></a>
<FONT color="green">040</FONT>    public class SunTimesCalculator extends AstronomicalCalculator {<a name="line.40"></a>
<FONT color="green">041</FONT>            private String calculatorName = "US Naval Almanac Algorithm";<a
        name="line.41"></a>
<FONT color="green">042</FONT>            public String getCalculatorName() {<a name="line.42"></a>
<FONT color="green">043</FONT>                    return calculatorName;<a name="line.43"></a>
<FONT color="green">044</FONT>            }<a name="line.44"></a>
<FONT color="green">045</FONT>    <a name="line.45"></a>
<FONT color="green">046</FONT>            /**<a name="line.46"></a>
<FONT color="green">047</FONT>             * @see net.sourceforge.zmanim.util.AstronomicalCalculator#getUTCSunrise(AstronomicalCalendar,<a
        name="line.47"></a>
<FONT color="green">048</FONT>             *      double, boolean)<a name="line.48"></a>
<FONT color="green">049</FONT>             */<a name="line.49"></a>
<FONT color="green">050</FONT>            public double getUTCSunrise(AstronomicalCalendar astronomicalCalendar,<a
        name="line.50"></a>
<FONT color="green">051</FONT>                            double zenith, boolean adjustForElevation) {<a
        name="line.51"></a>
<FONT color="green">052</FONT>                    double doubleTime = Double.NaN;<a name="line.52"></a>
<FONT color="green">053</FONT>    <a name="line.53"></a>
<FONT color="green">054</FONT>                    if (adjustForElevation) {<a name="line.54"></a>
<FONT color="green">055</FONT>                            zenith = adjustZenith(zenith, astronomicalCalendar.getGeoLocation()<a
        name="line.55"></a>
<FONT color="green">056</FONT>                                            .getElevation());<a name="line.56"></a>
<FONT color="green">057</FONT>                    } else {<a name="line.57"></a>
<FONT color="green">058</FONT>                            zenith = adjustZenith(zenith, 0);<a name="line.58"></a>
<FONT color="green">059</FONT>                    }<a name="line.59"></a>
<FONT color="green">060</FONT>                    doubleTime = getTimeUTC(astronomicalCalendar.getCalendar().get(<a
        name="line.60"></a>
<FONT color="green">061</FONT>                                    Calendar.YEAR), astronomicalCalendar.getCalendar().get(<a
        name="line.61"></a>
<FONT color="green">062</FONT>                                    Calendar.MONTH) + 1, astronomicalCalendar.getCalendar().get(<a
        name="line.62"></a>
<FONT color="green">063</FONT>                                    Calendar.DAY_OF_MONTH), astronomicalCalendar.getGeoLocation()<a
        name="line.63"></a>
<FONT color="green">064</FONT>                                    .getLongitude(), astronomicalCalendar.getGeoLocation()<a
        name="line.64"></a>
<FONT color="green">065</FONT>                                    .getLatitude(), zenith, TYPE_SUNRISE);<a
        name="line.65"></a>
<FONT color="green">066</FONT>                    return doubleTime;<a name="line.66"></a>
<FONT color="green">067</FONT>            }<a name="line.67"></a>
<FONT color="green">068</FONT>    <a name="line.68"></a>
<FONT color="green">069</FONT>            /**<a name="line.69"></a>
<FONT color="green">070</FONT>             * @see net.sourceforge.zmanim.util.AstronomicalCalculator#getUTCSunset(AstronomicalCalendar,<a
        name="line.70"></a>
<FONT color="green">071</FONT>             *      double, boolean)<a name="line.71"></a>
<FONT color="green">072</FONT>             */<a name="line.72"></a>
<FONT color="green">073</FONT>            public double getUTCSunset(AstronomicalCalendar astronomicalCalendar,<a
        name="line.73"></a>
<FONT color="green">074</FONT>                            double zenith, boolean adjustForElevation) {<a
        name="line.74"></a>
<FONT color="green">075</FONT>                    double doubleTime = Double.NaN;<a name="line.75"></a>
<FONT color="green">076</FONT>    <a name="line.76"></a>
<FONT color="green">077</FONT>                    if (adjustForElevation) {<a name="line.77"></a>
<FONT color="green">078</FONT>                            zenith = adjustZenith(zenith, astronomicalCalendar.getGeoLocation()<a
        name="line.78"></a>
<FONT color="green">079</FONT>                                            .getElevation());<a name="line.79"></a>
<FONT color="green">080</FONT>                    } else {<a name="line.80"></a>
<FONT color="green">081</FONT>                            zenith = adjustZenith(zenith, 0);<a name="line.81"></a>
<FONT color="green">082</FONT>                    }<a name="line.82"></a>
<FONT color="green">083</FONT>                    doubleTime = getTimeUTC(astronomicalCalendar.getCalendar().get(<a
        name="line.83"></a>
<FONT color="green">084</FONT>                                    Calendar.YEAR), astronomicalCalendar.getCalendar().get(<a
        name="line.84"></a>
<FONT color="green">085</FONT>                                    Calendar.MONTH) + 1, astronomicalCalendar.getCalendar().get(<a
        name="line.85"></a>
<FONT color="green">086</FONT>                                    Calendar.DAY_OF_MONTH), astronomicalCalendar.getGeoLocation()<a
        name="line.86"></a>
<FONT color="green">087</FONT>                                    .getLongitude(), astronomicalCalendar.getGeoLocation()<a
        name="line.87"></a>
<FONT color="green">088</FONT>                                    .getLatitude(), zenith, TYPE_SUNSET);<a
        name="line.88"></a>
<FONT color="green">089</FONT>                    return doubleTime;<a name="line.89"></a>
<FONT color="green">090</FONT>            }<a name="line.90"></a>
<FONT color="green">091</FONT>    <a name="line.91"></a>
<FONT color="green">092</FONT>            /**<a name="line.92"></a>
<FONT color="green">093</FONT>             * Default value for Sun's zenith and true rise/set<a name="line.93"></a>
<FONT color="green">094</FONT>             */<a name="line.94"></a>
<FONT color="green">095</FONT>            public static final double ZENITH = 90 + 50.0 / 60.0;<a name="line.95"></a>
<FONT color="green">096</FONT>    <a name="line.96"></a>
<FONT color="green">097</FONT>            private static final int TYPE_SUNRISE = 0;<a name="line.97"></a>
<FONT color="green">098</FONT>    <a name="line.98"></a>
<FONT color="green">099</FONT>            private static final int TYPE_SUNSET = 1;<a name="line.99"></a>
<FONT color="green">100</FONT>    <a name="line.100"></a>
<FONT color="green">101</FONT>            // DEG_PER_HOUR is the number of degrees of longitude<a name="line.101"></a>
<FONT color="green">102</FONT>            // that corresponds to one hour time difference.<a name="line.102"></a>
<FONT color="green">103</FONT>            private static final double DEG_PER_HOUR = 360.0 / 24.0;<a
        name="line.103"></a>
<FONT color="green">104</FONT>    <a name="line.104"></a>
<FONT color="green">105</FONT>            /**<a name="line.105"></a>
<FONT color="green">106</FONT>             * sin of an angle in degrees<a name="line.106"></a>
<FONT color="green">107</FONT>             */<a name="line.107"></a>
<FONT color="green">108</FONT>            private static double sinDeg(double deg) {<a name="line.108"></a>
<FONT color="green">109</FONT>                    return Math.sin(deg * 2.0 * Math.PI / 360.0);<a name="line.109"></a>
<FONT color="green">110</FONT>            }<a name="line.110"></a>
<FONT color="green">111</FONT>    <a name="line.111"></a>
<FONT color="green">112</FONT>            /**<a name="line.112"></a>
<FONT color="green">113</FONT>             * acos of an angle, result in degrees<a name="line.113"></a>
<FONT color="green">114</FONT>             */<a name="line.114"></a>
<FONT color="green">115</FONT>            private static double acosDeg(double x) {<a name="line.115"></a>
<FONT color="green">116</FONT>                    return Math.acos(x) * 360.0 / (2 * Math.PI);<a name="line.116"></a>
<FONT color="green">117</FONT>            }<a name="line.117"></a>
<FONT color="green">118</FONT>    <a name="line.118"></a>
<FONT color="green">119</FONT>            /**<a name="line.119"></a>
<FONT color="green">120</FONT>             * asin of an angle, result in degrees<a name="line.120"></a>
<FONT color="green">121</FONT>             */<a name="line.121"></a>
<FONT color="green">122</FONT>            private static double asinDeg(double x) {<a name="line.122"></a>
<FONT color="green">123</FONT>                    return Math.asin(x) * 360.0 / (2 * Math.PI);<a name="line.123"></a>
<FONT color="green">124</FONT>            }<a name="line.124"></a>
<FONT color="green">125</FONT>    <a name="line.125"></a>
<FONT color="green">126</FONT>            /**<a name="line.126"></a>
<FONT color="green">127</FONT>             * tan of an angle in degrees<a name="line.127"></a>
<FONT color="green">128</FONT>             */<a name="line.128"></a>
<FONT color="green">129</FONT>            private static double tanDeg(double deg) {<a name="line.129"></a>
<FONT color="green">130</FONT>                    return Math.tan(deg * 2.0 * Math.PI / 360.0);<a name="line.130"></a>
<FONT color="green">131</FONT>            }<a name="line.131"></a>
<FONT color="green">132</FONT>    <a name="line.132"></a>
<FONT color="green">133</FONT>            /**<a name="line.133"></a>
<FONT color="green">134</FONT>             * cos of an angle in degrees<a name="line.134"></a>
<FONT color="green">135</FONT>             */<a name="line.135"></a>
<FONT color="green">136</FONT>            private static double cosDeg(double deg) {<a name="line.136"></a>
<FONT color="green">137</FONT>                    return Math.cos(deg * 2.0 * Math.PI / 360.0);<a name="line.137"></a>
<FONT color="green">138</FONT>            }<a name="line.138"></a>
<FONT color="green">139</FONT>    <a name="line.139"></a>
<FONT color="green">140</FONT>            /**<a name="line.140"></a>
<FONT color="green">141</FONT>             * Calculate the day of the year, where Jan 1st is day 1. Note that this<a
        name="line.141"></a>
<FONT color="green">142</FONT>             * method needs to know the year, because leap years have an impact here<a
        name="line.142"></a>
<FONT color="green">143</FONT>             */<a name="line.143"></a>
<FONT color="green">144</FONT>            private static int getDayOfYear(int year, int month, int day) {<a
        name="line.144"></a>
<FONT color="green">145</FONT>                    int n1 = 275 * month / 9;<a name="line.145"></a>
<FONT color="green">146</FONT>                    int n2 = (month + 9) / 12;<a name="line.146"></a>
<FONT color="green">147</FONT>                    int n3 = (1 + ((year - 4 * (year / 4) + 2) / 3));<a
        name="line.147"></a>
<FONT color="green">148</FONT>                    int n = n1 - (n2 * n3) + day - 30;<a name="line.148"></a>
<FONT color="green">149</FONT>                    return n;<a name="line.149"></a>
<FONT color="green">150</FONT>            }<a name="line.150"></a>
<FONT color="green">151</FONT>    <a name="line.151"></a>
<FONT color="green">152</FONT>            /**<a name="line.152"></a>
<FONT color="green">153</FONT>             * Get time difference between location's longitude and the Meridian, in<a
        name="line.153"></a>
<FONT color="green">154</FONT>             * hours. West of Meridian has a negative time difference<a
        name="line.154"></a>
<FONT color="green">155</FONT>             */<a name="line.155"></a>
<FONT color="green">156</FONT>            private static double getHoursFromMeridian(double longitude) {<a
        name="line.156"></a>
<FONT color="green">157</FONT>                    return longitude / DEG_PER_HOUR;<a name="line.157"></a>
<FONT color="green">158</FONT>            }<a name="line.158"></a>
<FONT color="green">159</FONT>    <a name="line.159"></a>
<FONT color="green">160</FONT>            /**<a name="line.160"></a>
<FONT color="green">161</FONT>             * Gets the approximate time of sunset or sunrise In _days_ since midnight<a
        name="line.161"></a>
<FONT color="green">162</FONT>             * Jan 1st, assuming 6am and 6pm events. We need this figure to derive the<a
        name="line.162"></a>
<FONT color="green">163</FONT>             * Sun's mean anomaly<a name="line.163"></a>
<FONT color="green">164</FONT>             */<a name="line.164"></a>
<FONT color="green">165</FONT>            private static double getApproxTimeDays(int dayOfYear,<a name="line.165"></a>
<FONT color="green">166</FONT>                            double hoursFromMeridian, int type) {<a name="line.166"></a>
<FONT color="green">167</FONT>                    if (type == TYPE_SUNRISE) {<a name="line.167"></a>
<FONT color="green">168</FONT>                            return dayOfYear + ((6.0 - hoursFromMeridian) / 24);<a
        name="line.168"></a>
<FONT color="green">169</FONT>                    } else /* if (type == TYPE_SUNSET) */{<a name="line.169"></a>
<FONT color="green">170</FONT>                            return dayOfYear + ((18.0 - hoursFromMeridian) / 24);<a
        name="line.170"></a>
<FONT color="green">171</FONT>                    }<a name="line.171"></a>
<FONT color="green">172</FONT>            }<a name="line.172"></a>
<FONT color="green">173</FONT>    <a name="line.173"></a>
<FONT color="green">174</FONT>            /**<a name="line.174"></a>
<FONT color="green">175</FONT>             * Calculate the Sun's mean anomaly in degrees, at sunrise or sunset, given<a
        name="line.175"></a>
<FONT color="green">176</FONT>             * the longitude in degrees<a name="line.176"></a>
<FONT color="green">177</FONT>             */<a name="line.177"></a>
<FONT color="green">178</FONT>            private static double getMeanAnomaly(int dayOfYear, double longitude,<a
        name="line.178"></a>
<FONT color="green">179</FONT>                            int type) {<a name="line.179"></a>
<FONT color="green">180</FONT>                    return (0.9856 * getApproxTimeDays(dayOfYear,<a name="line.180"></a>
<FONT color="green">181</FONT>                                    getHoursFromMeridian(longitude), type)) - 3.289;<a
        name="line.181"></a>
<FONT color="green">182</FONT>            }<a name="line.182"></a>
<FONT color="green">183</FONT>    <a name="line.183"></a>
<FONT color="green">184</FONT>            /**<a name="line.184"></a>
<FONT color="green">185</FONT>             * Calculates the Sun's true longitude in degrees. The result is an angle<a
        name="line.185"></a>
<FONT color="green">186</FONT>             * gte 0 and lt 360. Requires the Sun's mean anomaly, also in degrees<a
        name="line.186"></a>
<FONT color="green">187</FONT>             */<a name="line.187"></a>
<FONT color="green">188</FONT>            private static double getSunTrueLongitude(double sunMeanAnomaly) {<a
        name="line.188"></a>
<FONT color="green">189</FONT>                    double l = sunMeanAnomaly + (1.916 * sinDeg(sunMeanAnomaly))<a
        name="line.189"></a>
<FONT color="green">190</FONT>                                    + (0.020 * sinDeg(2 * sunMeanAnomaly)) + 282.634;<a
        name="line.190"></a>
<FONT color="green">191</FONT>    <a name="line.191"></a>
<FONT color="green">192</FONT>                    // get longitude into 0-360 degree range<a name="line.192"></a>
<FONT color="green">193</FONT>                    if (l &gt;= 360.0) {<a name="line.193"></a>
<FONT color="green">194</FONT>                            l = l - 360.0;<a name="line.194"></a>
<FONT color="green">195</FONT>                    }<a name="line.195"></a>
<FONT color="green">196</FONT>                    if (l &lt; 0) {<a name="line.196"></a>
<FONT color="green">197</FONT>                            l = l + 360.0;<a name="line.197"></a>
<FONT color="green">198</FONT>                    }<a name="line.198"></a>
<FONT color="green">199</FONT>                    return l;<a name="line.199"></a>
<FONT color="green">200</FONT>            }<a name="line.200"></a>
<FONT color="green">201</FONT>    <a name="line.201"></a>
<FONT color="green">202</FONT>            /**<a name="line.202"></a>
<FONT color="green">203</FONT>             * Calculates the Sun's right ascension in hours, given the Sun's true<a
        name="line.203"></a>
<FONT color="green">204</FONT>             * longitude in degrees. Input and output are angles gte 0 and lt 360.<a
        name="line.204"></a>
<FONT color="green">205</FONT>             */<a name="line.205"></a>
<FONT color="green">206</FONT>            private static double getSunRightAscensionHours(double sunTrueLongitude) {<a
        name="line.206"></a>
<FONT color="green">207</FONT>                    double a = 0.91764 * tanDeg(sunTrueLongitude);<a name="line.207"></a>
<FONT color="green">208</FONT>                    double ra = 360.0 / (2.0 * Math.PI) * Math.atan(a);<a
        name="line.208"></a>
<FONT color="green">209</FONT>                    // get result into 0-360 degree range<a name="line.209"></a>
<FONT color="green">210</FONT>                    // if (ra &gt;= 360.0) ra = ra - 360.0;<a name="line.210"></a>
<FONT color="green">211</FONT>                    // if (ra &lt; 0) ra = ra + 360.0;<a name="line.211"></a>
<FONT color="green">212</FONT>    <a name="line.212"></a>
<FONT color="green">213</FONT>                    double lQuadrant = Math.floor(sunTrueLongitude / 90.0) * 90.0;<a
        name="line.213"></a>
<FONT color="green">214</FONT>                    double raQuadrant = Math.floor(ra / 90.0) * 90.0;<a
        name="line.214"></a>
<FONT color="green">215</FONT>                    ra = ra + (lQuadrant - raQuadrant);<a name="line.215"></a>
<FONT color="green">216</FONT>    <a name="line.216"></a>
<FONT color="green">217</FONT>                    return ra / DEG_PER_HOUR; // convert to hours<a name="line.217"></a>
<FONT color="green">218</FONT>            }<a name="line.218"></a>
<FONT color="green">219</FONT>    <a name="line.219"></a>
<FONT color="green">220</FONT>            /**<a name="line.220"></a>
<FONT color="green">221</FONT>             * Gets the cosine of the Sun's local hour angle<a name="line.221"></a>
<FONT color="green">222</FONT>             */<a name="line.222"></a>
<FONT color="green">223</FONT>            private static double getCosLocalHourAngle(double sunTrueLongitude,<a
        name="line.223"></a>
<FONT color="green">224</FONT>                            double latitude, double zenith) {<a name="line.224"></a>
<FONT color="green">225</FONT>                    double sinDec = 0.39782 * sinDeg(sunTrueLongitude);<a
        name="line.225"></a>
<FONT color="green">226</FONT>                    double cosDec = cosDeg(asinDeg(sinDec));<a name="line.226"></a>
<FONT color="green">227</FONT>    <a name="line.227"></a>
<FONT color="green">228</FONT>                    double cosH = (cosDeg(zenith) - (sinDec * sinDeg(latitude)))<a
        name="line.228"></a>
<FONT color="green">229</FONT>                                    / (cosDec * cosDeg(latitude));<a name="line.229"></a>
<FONT color="green">230</FONT>    <a name="line.230"></a>
<FONT color="green">231</FONT>                    // Check bounds<a name="line.231"></a>
<FONT color="green">232</FONT>    <a name="line.232"></a>
<FONT color="green">233</FONT>                    return cosH;<a name="line.233"></a>
<FONT color="green">234</FONT>            }<a name="line.234"></a>
<FONT color="green">235</FONT>    <a name="line.235"></a>
<FONT color="green">236</FONT>            /**<a name="line.236"></a>
<FONT color="green">237</FONT>             * Gets the cosine of the Sun's local hour angle for default zenith<a
        name="line.237"></a>
<FONT color="green">238</FONT>             */<a name="line.238"></a>
<FONT color="green">239</FONT>    //      private static double getCosLocalHourAngle(double sunTrueLongitude,<a
        name="line.239"></a>
<FONT color="green">240</FONT>    //                      double latitude) {<a name="line.240"></a>
<FONT color="green">241</FONT>    //              return getCosLocalHourAngle(sunTrueLongitude, latitude, ZENITH);<a
        name="line.241"></a>
<FONT color="green">242</FONT>    //      }<a name="line.242"></a>
<FONT color="green">243</FONT>    <a name="line.243"></a>
<FONT color="green">244</FONT>            /**<a name="line.244"></a>
<FONT color="green">245</FONT>             * Calculate local mean time of rising or setting. By `local' is meant the<a
        name="line.245"></a>
<FONT color="green">246</FONT>             * exact time at the location, assuming that there were no time zone. That<a
        name="line.246"></a>
<FONT color="green">247</FONT>             * is, the time difference between the location and the Meridian depended<a
        name="line.247"></a>
<FONT color="green">248</FONT>             * entirely on the longitude. We can't do anything with this time directly;<a
        name="line.248"></a>
<FONT color="green">249</FONT>             * we must convert it to UTC and then to a local time. The result is<a
        name="line.249"></a>
<FONT color="green">250</FONT>             * expressed as a fractional number of hours since midnight<a
        name="line.250"></a>
<FONT color="green">251</FONT>             */<a name="line.251"></a>
<FONT color="green">252</FONT>            private static double getLocalMeanTime(double localHour,<a
        name="line.252"></a>
<FONT color="green">253</FONT>                            double sunRightAscensionHours, double approxTimeDays) {<a
        name="line.253"></a>
<FONT color="green">254</FONT>                    return localHour + sunRightAscensionHours - (0.06571 * approxTimeDays)<a
        name="line.254"></a>
<FONT color="green">255</FONT>                                    - 6.622;<a name="line.255"></a>
<FONT color="green">256</FONT>            }<a name="line.256"></a>
<FONT color="green">257</FONT>    <a name="line.257"></a>
<FONT color="green">258</FONT>            /**<a name="line.258"></a>
<FONT color="green">259</FONT>             * Get sunrise or sunset time in UTC, according to flag.<a
        name="line.259"></a>
<FONT color="green">260</FONT>             *<a name="line.260"></a>
<FONT color="green">261</FONT>             * @param year<a name="line.261"></a>
<FONT color="green">262</FONT>             *            4-digit year<a name="line.262"></a>
<FONT color="green">263</FONT>             * @param month<a name="line.263"></a>
<FONT color="green">264</FONT>             *            month, 1-12 (not the zero based Java month<a
        name="line.264"></a>
<FONT color="green">265</FONT>             * @param day<a name="line.265"></a>
<FONT color="green">266</FONT>             *            day of month, 1-31<a name="line.266"></a>
<FONT color="green">267</FONT>             * @param longitude<a name="line.267"></a>
<FONT color="green">268</FONT>             *            in degrees, longitudes west of Meridian are negative<a
        name="line.268"></a>
<FONT color="green">269</FONT>             * @param latitude<a name="line.269"></a>
<FONT color="green">270</FONT>             *            in degrees, latitudes south of equator are negative<a
        name="line.270"></a>
<FONT color="green">271</FONT>             * @param zenith<a name="line.271"></a>
<FONT color="green">272</FONT>             *            Sun's zenith, in degrees<a name="line.272"></a>
<FONT color="green">273</FONT>             * @param type<a name="line.273"></a>
<FONT color="green">274</FONT>             *            type of calculation to carry out {@link #TYPE_SUNRISE} or<a
        name="line.274"></a>
<FONT color="green">275</FONT>             *            {@link #TYPE_SUNRISE}.<a name="line.275"></a>
<FONT color="green">276</FONT>             *<a name="line.276"></a>
<FONT color="green">277</FONT>             * @return the time as a double. If an error was encountered in the<a
        name="line.277"></a>
<FONT color="green">278</FONT>             *         calculation (expected behavior for some locations such as near<a
        name="line.278"></a>
<FONT color="green">279</FONT>             *         the poles, {@link Double.NaN} will be returned.<a
        name="line.279"></a>
<FONT color="green">280</FONT>             */<a name="line.280"></a>
<FONT color="green">281</FONT>            private static double getTimeUTC(int year, int month, int day,<a
        name="line.281"></a>
<FONT color="green">282</FONT>                            double longitude, double latitude, double zenith, int type) {<a
        name="line.282"></a>
<FONT color="green">283</FONT>                    int dayOfYear = getDayOfYear(year, month, day);<a name="line.283"></a>
<FONT color="green">284</FONT>                    double sunMeanAnomaly = getMeanAnomaly(dayOfYear, longitude, type);<a
        name="line.284"></a>
<FONT color="green">285</FONT>                    double sunTrueLong = getSunTrueLongitude(sunMeanAnomaly);<a
        name="line.285"></a>
<FONT color="green">286</FONT>                    double sunRightAscensionHours = getSunRightAscensionHours(sunTrueLong);<a
        name="line.286"></a>
<FONT color="green">287</FONT>                    double cosLocalHourAngle = getCosLocalHourAngle(sunTrueLong, latitude,<a
        name="line.287"></a>
<FONT color="green">288</FONT>                                    zenith);<a name="line.288"></a>
<FONT color="green">289</FONT>    <a name="line.289"></a>
<FONT color="green">290</FONT>                    double localHourAngle = 0;<a name="line.290"></a>
<FONT color="green">291</FONT>                    if (type == TYPE_SUNRISE) {<a name="line.291"></a>
<FONT color="green">292</FONT>                            if (cosLocalHourAngle &gt; 1) { // no rise. No need for an Exception<a
        name="line.292"></a>
<FONT color="green">293</FONT>                                    // since the calculation<a name="line.293"></a>
<FONT color="green">294</FONT>                                    // will return Double.NaN<a name="line.294"></a>
<FONT color="green">295</FONT>                            }<a name="line.295"></a>
<FONT color="green">296</FONT>                            localHourAngle = 360.0 - acosDeg(cosLocalHourAngle);<a
        name="line.296"></a>
<FONT color="green">297</FONT>                    } else /* if (type == TYPE_SUNSET) */{<a name="line.297"></a>
<FONT color="green">298</FONT>                            if (cosLocalHourAngle &lt; -1) {// no SET. No need for an Exception<a
        name="line.298"></a>
<FONT color="green">299</FONT>                                    // since the calculation<a name="line.299"></a>
<FONT color="green">300</FONT>                                    // will return Double.NaN<a name="line.300"></a>
<FONT color="green">301</FONT>                            }<a name="line.301"></a>
<FONT color="green">302</FONT>                            localHourAngle = acosDeg(cosLocalHourAngle);<a
        name="line.302"></a>
<FONT color="green">303</FONT>                    }<a name="line.303"></a>
<FONT color="green">304</FONT>                    double localHour = localHourAngle / DEG_PER_HOUR;<a
        name="line.304"></a>
<FONT color="green">305</FONT>    <a name="line.305"></a>
<FONT color="green">306</FONT>                    double localMeanTime = getLocalMeanTime(localHour,<a
        name="line.306"></a>
<FONT color="green">307</FONT>                                    sunRightAscensionHours, getApproxTimeDays(dayOfYear,<a
        name="line.307"></a>
<FONT color="green">308</FONT>                                                    getHoursFromMeridian(longitude), type));<a
        name="line.308"></a>
<FONT color="green">309</FONT>                    double pocessedTime = localMeanTime - getHoursFromMeridian(longitude);<a
        name="line.309"></a>
<FONT color="green">310</FONT>                    while (pocessedTime &lt; 0.0) {<a name="line.310"></a>
<FONT color="green">311</FONT>                            pocessedTime += 24.0;<a name="line.311"></a>
<FONT color="green">312</FONT>                    }<a name="line.312"></a>
<FONT color="green">313</FONT>                    while (pocessedTime &gt;= 24.0) {<a name="line.313"></a>
<FONT color="green">314</FONT>                            pocessedTime -= 24.0;<a name="line.314"></a>
<FONT color="green">315</FONT>                    }<a name="line.315"></a>
<FONT color="green">316</FONT>                    return pocessedTime;<a name="line.316"></a>
<FONT color="green">317</FONT>            }<a name="line.317"></a>
<FONT color="green">318</FONT>    <a name="line.318"></a>
<FONT color="green">319</FONT>    }<a name="line.319"></a>




























































</PRE>
</BODY>
</HTML>
